I've got an out of the box question that I thought somebody here might have some insight on. I've got an interesting photo/video gig coming up that has some unique technical challenges. I'm going to be shooting a Bikram Yoga demonstration. What's Bikram Yoga? It's the yoga that is done in a REALLY hot room - Bikram Yoga is ideally practiced in a room heated to 105°F (≈ 40.6°C) with a humidity of 40%. (for more on Bikram check this out - http://en.wikipedia.org/wiki/Bikram_Yoga)

I'm going to be in the room - there's no way around that and the demo will likely last about an hour. I want to shoot it with my Canon 7D - but i'm concerned/curious about the affect of the heat and humidity on the gear? beynd things fogging up and a very oncomfortable photographer, how well sealed is the 7D and will I risk killing it by shooting in this environment?

My back-up plan is to shoot the video with my GoPro HD Hero2 which I know can handle it, but I really wanted to use my 7D for the project.

40% humidity isn't high. It's about mid to low in the comfort zone for humans. Nothing to worry about. 40C is more of a comfort issue for you than the camera. Actually, I'm not sure what working temperature the camera is rated at, should be in the manual if you want to double check.

I think at worst when you go in, you might get a little condensation that will clear once the temperature is stabilised. After that, shoot normally. Some people use a sealed bag trick but I've never bothered myself.

I listened to a Dirt Bag Diaries podcast with an interview of a photographer who had needed to do the same shoot. The sealed bag trick worked, once the camera was warm enough there were no condensation problems it was just him that sweated his nuts off. Make sure you take some shorts, he had to borrow some out of lost property. When he was in the changing room afterwards another guy identified them as ones he was missing but also apologised as he had crotch rot ha ha.

1) Make sure you are using a sealed lens too or you lose that seal. No point in having a sealed camera if its not sealed through the lens mount
2) Ask the people who control the temperature and the humidity to let you know WHEN they stopped upping the temp and humidity. THAT is your start point because...
3) Dont start shooting right away - give your camera 5-10 mins before you start shooting or condensation will kill your camera (It killed my video camera once, thank goodness it was only my back up camera.
4) Set up your settings b4 you enter so the only buttons and stuff you push is the: ON button, the Shutter button and the zoom etc.
5) I normally put tape over the mic holes and tape over the left side - I know its sealed but I once realised that I personally didnt push in one corner all the way properly and condensation started to from at the corner, luckily it was small and didnt get into the internals but hey better safe than sorry (btw I used Gaffa tape since it doesnt leave residue)
6) Turn off your camera WHILE you are in the room, not after. You want your camera to be off when you leave so if condensation happens and all that outside, you dont want anything to be running a current. Then leave your camera for 10-15 mins and then you can turn it on again.

Minus the tape I use, I only do this when I enter a steamy environment (not so much a hot one) OR when I enter a COLD COLD environment from a hot one - so when I go to the snow, I cant start shooting until 10 mins after I leave the lodge. and 10 mins when I go back in where its warm and humid.

I was in Mildura in November for a week and one day while fishing along the Murray River it was a pleasant 41 C, due to the rain the previous night and being next to the river, the humidity was high. Not sure how high now.
It was pleasant fishing in the shade with a slight breeze and the odd beer or two.

The 7D and the 70-300L had been in a backpack with the sun shining on it, it was working fine when I pulled it out to photograph some parrots. On the drive back on the dirt road along the river, I stopped frequently to chase birds. Jumping from air conditioned car and out in the hot day, had no effect on the camera or lens at all.

You will not have a breeze so some loose cool clothing so you can sweat easily might be useful, I personally wouldn`t be worried about the camera or lens as 40% humidity isn`t that high.

Ah I just do it as a precaution - I film a lot of snow and sking and I had a few things lock up on me and once a friends video camera went kaput.

The stuff that locks up on me, for example, not turning on or malfunctioning etc resolves itself once the temps have eased.

Of course this is extreme cold and SLR cameras are much simpler in design than video cameras and a 7D is more robust, but Id thought Id communicate precautions if you are still not 100% about the situation.

I bought a 7D purely for the fact that during sports days the kids play with water guns and buckets, they wont do it to a teacher with a camera but its only a precaution.